Logic for improved delta pressure based soot estimation on low restriction particulate filters

A vehicle having an exhaust system implementing delta pressure based estimation of accumulated soot within a diesel particulate filter, comprising:

• an engine connected to an exhaust system, the exhaust system having therein a diesel oxidation catalyst and a diesel particulate filter;
• a fuel injector device connected to the exhaust system upstream from the diesel oxidation catalyst and the diesel particulate filter;
• a delta exhaust pressure sensor arrangement configured to measure a difference in exhaust pressure at an inlet to the diesel particulate filter and at an outlet to the diesel particulate filter;
• and
• at least one controller connected to the fuel injector and to the delta exhaust pressure sensor arrangement, and being configured to:
• 1.) determine when to conduct an active regeneration of the diesel particulate filter based on an estimated amount of soot accumulated therein;
• 2.) in a first regeneration mode, cause the fuel injector device to inject fuel at a first rate into the exhaust stream, and re-evaluate amount of soot accumulated within the diesel particulate filter under increased volumetric flow of the exhaust stream;
• and
• 3.) in a second regeneration mode, cause the fuel injector device to inject fuel at a second rate into the exhaust stream in order to combust soot trapped in the diesel particulate filter.